Method for constructing a frame structure with load-bearing joints

ABSTRACT

A method of making and erecting a framed structure, preferably single level, by milling standard pieces of lumber that are joined into a sturdy, rectangular frame is disclosed. Opposed Side Beams having dado cuts at their opposite ends are joined to opposed Face Beams having complementary dado cuts at their opposite ends. Floor joists connect opposed sidebeams and support subflooring or decking, and, to accommodate certain larger dimensional floorplans, Center Beams are built into the frame. The frame can rest on a periphery foundation or be erected over posts.

This application is a continuation of application Ser. No. 07/539,124,filed Jun. 18, 1990 now abandoned.

BACKGROUND OF THE INVENTION

The costs of new housing construction have spiralled upward throughoutthe last years, and many potential buyers of new homes have decided tostay in their current home and simply make additions to the existingstructure. One addition that has become popular is to add a deck, orother framed structure, to an existing house. Many popular framed,deck-kits are available to homeowners who wish to follow instructions orthere are a number of national or local companies that will not onlysupply the lumber and hardware, but also build the structure at adesired location.

Of the many popular deck styles currently available, problems with thespecific design or the construction techniques needed may causedissatisfaction with the finished product. One major problem with somekits is that, to finally end up with a well-built and estheticallypleasing structure, a very large number of "finish" pieces must benailed over the basic skeletal structure, to cover up unsightly joints.This increases the cost of the finished product and of course, with manypieces to use, adds to the time necessary to complete the project. Manydesigns advertise that load-bearing joints, or where the center of massof all weight (no matter what the height), rest firmly on and over thefoundation, are utilized at the junction of posts and beams, when infact the construction is only partially load-bearing because the beam isnailed into a cleft the size of the width and depth of the beam on theedge of the post. This construction brings with it a number ofstructural weaknesses: for instance, in the first place the cleft in a4"×4" post, for example, is only 11/2" in depth and not in the center ofthe beam. If the post dimensions are 4"4" (which, in reality is only31/2"×31/2"), only 43% of the cross-sectional area of the post providesthe support. Also, since nails are put in transverse to the direction ofthe load, any separation of these members at the cleft will weaken thejunction.

Another common practice in current constructed frame decks oradditional, framed rooms is to join the joists to the side beams by thecommon lap joint. Use of this technique, where part of either end of theJoist is cut away and these sections are fittingly joined intoappropriately sized cut away spaces in the side or facing beams, onlyprovides a partial support at the junction because of the missingsections of both the joist and beam.

SUMMARY OF THE INVENTION

A method of making and erecting a framed deck, or an additional framedroom for a house or other structure and the deck or structure so madethereby is claimed. Pre-fabricated members, engineered and made fromrectangular-shaped lengths of solid or laminated wood to allow singlepiece per end and side and having, along their longitudinal dimensions,a plurality of dado-cuts milled in the surface with transverse-orientednotches cut therein and at opposite ends, additional dado cuts therein,are joined to form members of a rectangular frame. Joists are set intoopposed notches on the beams and post cavities are cut at opposite endsof the lengths to receive vertical posts. Either decking or sub-flooringis set over the frame to form a horizontal platform and additionalstories can be added by setting second or third sets of posts, framemembers and joists thereon.

OBJECTS OF THE INVENTION

It is therefore an object of the present invention to provide a new andunique method for forming individual pieces, and erecting a structuretherefrom, that will provide strong joints at load-bearing junctures.

It is a further object of the present invention to provide a newtechnique for erecting a structure that utilizes side and face beamsformed to join at corners, that have opposed, mirror-imaged dado cutstherein to give greater strength.

It is a still further object of the present invention to provideuniquely formed beams that are formed together in a frame that givesprotection to the edge and butt end of floor boards.

It is still a further object of the present invention to produce araised deck frame structure with load bearing junctions set upon posts.

These and other objects of the present invention will become apparentafter reading the detailed description of the preferred embodiment andappended claims with reference to the attached drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a perspective view of a preferred embodiment of asingle-level, raised deck (with the floor boards partially cut-away toreveal corner and floor joist junctions) set upon Corner, Side and FacePosts;

FIG. 2 is an exploded, fragmentary view of a corner junction of the Deckof FIG. 1 showing details of the joined faces of a Side Beam, a FaceBeam and a lower-level Corner Post, with an upper-level Corner Postshown in phantom and showing an alternate sub-flooring (shown partiallycut-away) installed;

FIG. 3 is an exploded, fragmentary view of a Side or Face Beam junctionof the Deck of FIG. 1 showing details of the joined faces of a Face orSide Beam and a lower-level Face and Side Post (with an Upper-level Faceand Side Post shown in phantom) and with an alternate sub-flooring(shown partially cut-away) installed;

FIG. 4 is a perspective view of an alternate embodiment of theconstruction of FIG. 1 showing a one-story Deck with an installedsub-flooring (shown partially cut-away);

FIG. 5 is an exploded, fragmentary view of a Side or Face Beam junctionof the Deck of FIG. 4 showing details of the joined faces of a Face orSide Beam, a Center Beam and a lower-level Extension Post (with anupper-level Face and Side Post and a floor joist shown in phantom); and

FIG. 6 is an exploded, fragmentary view of a Center Beam junction of theDeck of FIG. 4 showing details of the joined faces of a Center Beam anda lower level Center Post (with an upper-level Center Post and floorjoist shown in phantom).

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT

One embodiment of the present invention is shown as a single level,raised Deck 20 as seen in FIG. 1. Deck 20 is comprised of a frame 21,composed of oppositely-facing Face Beams 22a, b joined at their ends (aswill be explained) to oppositely facing Side Beams 24a, b and at theirintermediate sections by joists 26, and alternatively, supported by aplurality of Face and Side Posts 28 and Corner Posts 30 with a pinjoining the frame to the posts, and covered by a layer, such as deckingplanks 33 (shown partially cut-away). Depending upon the directions forerection, Deck 20 can have frame 21 atop posts 28, 30 which arethemselves fastened into the walls of a foundation (not shown) or frame21 can be attached directly to a foundation, such as a four-foot footingaround the perimeter (also not shown) of the structure. Wooden pegs, ordowels, 36 or similar fastening means are used instead of standard metalnails or screws to fasten selected members together and, as will beexplained, certain members are held together by the forces of gravity.The wooden members used to erect Deck 20 can be made from any number ofdifferent woods, however where the deck is exposed to elements of theopen air the wooden members are preferably natural heartwood cedar orredwood to produce the most fungal-resistant and insect-resistantstructure. Each member is formed with a substantially rectangularcross-sectional area throughout its longitudinal dimension untilspecific cuts or notches are made therein.

FIG. 2 shows an exploded, fragmentary view of a corner junction 50formed by the combination of the ends of Face Beam 22b and Side Beam 24awith an upper-level post 30 (in phantom). If the framework 21 is to reston posts, the end of Corner Post 30 is joined thereto, as will beexplained. Face Beam 22b, a right Face Beam in FIG. 2, has an initialcross-sectional area that is substantially rectangular, as the beam canbe selected from the products found in most mills and lumber yards. Thebeam is pre-engineered to the design shown by milling a firstprespecified dado cut 38, using standard known carpentry techniques,from the top surface of the beam and by milling a second, prespecifieddado cut 39 from the bottom surface thereof. After both dado cuts havebeen made, the resulting structure has a square-edged groove cut intotwo adjoining surfaces to give a cross-sectional appearance of asideways "Z" with an upper surface face 32 and a lower surface 34.

For example, when using a 6"×12" beam that is 51/2"×111/2" (top surfacewidth by side surface width), the first cut is 4 inches wide by 11/2inches deep in the top surface along the total length of the beam andthe second cut is 21/2 inches wide by 41/2 inches deep in the adjoiningsurface. This first cut leaves a rim-like projection 41 extending alongthe member, which projection forms a natural finish or protectivesurface for the edge and butt ends of decking 33 or sub-flooring 31. Aplurality of notches 27b, each having substantially right-angledcorners, are cut out of the newly-exposed edge thereof for floor joists26 (shown in phantom) in FIG. 2. Opposed Face Beam 22a has similar dadocuts and notches therein, to present a "mirror image" when the two beamsare set opposite one another.

Opposed Side Beams 24a, b are also engineered in a similar fashion, withtwo dado cuts milled along top and outside surfaces, as explained above(only Side Beam 24a shown in FIG. 2). When a floor joist 26 (seen inphantom in FIG. 2) is to join opposed Face Beam 22a, b, notches 27a, b(only 27b seen in FIG. 2) are cut at appropriate intervals into thesurface newly-formed by dado cut 38. Three-dimensional sections equal tothe outside dimensions of height, width and a prespecified length of theends of joists 26 are removed, as by appropriate jigsaw cuts, atspecified intervals from opposed beams to form notches 27 for theopposed ends of joists 26. Joists 26 can be used to support decking 33or subflooring 31.

Also as shown in FIG. 2, corner junction 50 is formed by combiningcomplementary faces of the ends of Face Beams 22 and Side Beams 24 (only22b and 24a shown in FIG. 2). Two dado cuts, 61 and 63, are made with,for instance, a proper tool with skill known in the art, atpredetermined sections at the end of Face Beam 22b, with cut 61 onlygoing in partially and removing a section of wood the entire height ofthe beam, and cut 63 only going in partially and removing a section ofwood the entire width of the beam, as shown. As can be seen at the endof Face Beam 22b, cut 61 is made therein to leave vertical face 68 andrim 41 extending past and around the end thereof, and cut 63 is madetherein to leave vertical face 69 and lower horizontal face 65.

The joining faces, horizontal face 77 and vertical faces 78 and 79, ofSide Beam 24a are made by first making, as with a jigsaw or otherdevice, two orthogonal, vertical cuts 71 and 73, a predetermineddistance partially through the end and a horizontal, or orthogonal, cut75 to Join therewith and removing the part of wood separated thereby.The ends of Face Beam 22b and Side Beam 24a are joined at correspondingfaces 41--41, 68-78, 65-77, inner surface of Face Beam 22b-79, and innersurface of Side Beam 24a-69. "Corresponding faces 41--41" means that theface 41 of Face Beam 22b and the face 41 of Side Beam 24a confront eachother when Face Beam 22b and Side Beam 24a are joined. Similarly,"68-78" means that face 68 and face 78 confront each other when thebeams are joined, and so on.

Corner Posts 30 are engineered to provide, at the end joined to junction50, a two-sided seat 80 for the combination of the ends of Face Beam andSide Beam 22b, 24a, respectively, to fit into. As seen in FIG. 2, an endof post 30 has a first cut made along a plane substantially parallel toa side thereof and into the end of the post a predetermined distance, asecond cut made along a plane substantially parallel to theperpendicular side thereof and into the end of the post a predetermineddistance, and a third cut made transversely to said first and secondcuts, at the predetermined distance to separate a substantially cubicalsection of wood therefrom to form seat 80. The first cut providesvertical face 85 and the second cut provides vertical face 86 and thethird cut provides horizontal face 87.

The combination of the vertical surfaces of dado cuts 39 of the ends ofFace Beam 22b and Side Beam 24a are fittingly joined to correspondingvertical faces 86 and 85, respectively, of Post 30 and therefore preventjunction 50 from any degree of freedom in the horizontal direction. Thecombination of the horizontal surfaces of dado cuts 39 and lowersurfaces 34 of the ends of Face Beam 22b and Side Beam 24a are fittinglyjoined to corresponding horizontal top faces 86 and 85, and face 87,respectively, of Post 30. Since the horizontal surfaces of dado cut 39and lower surfaces 34 of Face Beam 22b and Side Beam 24a rest entirelyon the horizontal cross-sectional area of Post 30, the joined horizontalfaces 65-77 of Face Beam 22b and Side Beam 24a do not bear the weight ofany load on junction 50, (thus a "load-bearing" surface is one thatbears no load) nor on Deck 20. An aperture 88 is bored perpendicular tothe upper surface of junction 50, through beams 22b and 24 a and intoface 87 and fastening means, such as a pin 36, inserted therein. If asub-flooring 31 or decking 33 is to be installed (as shown in FIGS. 1and 4), pin 36, and other fastening means (not shown in FIGS. 1 and 4)are used to secure it to frame 21. Also, as shown in phantom, asecond-level Post 28, 30, 128, or 228 can be fitted, by making aninverse dado cut shape to two-sided seat formed by rim 41 to fittinglyjoin the corresponding top surface of sub-flooring 31. By using theabove-described construction, junction 50 is held together by the forcesof gravity. In this way, the more weight added to Deck 20, the tighterand more secure, over and above the security built therein, it will be.

FIG. 3 shows an isolated and exploded view of a junction 100 taken fromnumeral III of FIG. 1. Junction 100 is formed by the combination of aFace or Side Post 28 and a Face Beam (not shown) or Side Beam such as24a. At predetermined intervals, a square notch 105 is cut, as with atool for making a dado cut or other similar means, from the underside ofthe beam, forming vertical faces of prespecified dimensions 109a and109b and horizontal face 108. The end of post 28 that is to be joinedinto Side Beam 24a has a pair of opposed notches 112a and 112b cuttherein to form vertical faces 114, 115, and 116 (only 114a, 115a, and116a are shown in FIG. 3) and horizontal faces 113a and 113b (only 113ais shown in FIG. 3), and give the end of Post 28 a cross-sectional areashaped similarly to the letter "H". The combination of the verticalsurfaces of dado cut 39, the vertical faces 109a and 109b and the innersurface of Side Beam 24a are fittingly joined to corresponding verticalfaces 114, 116, and 115 respectively of Post 28 and thus preventingjunction 100 from any degree of freedom in the horizontal direction. Thecombination of the horizontal surfaces of dado cut 39 and lower surface34 of Side Beam 24a are fittingly joined to corresponding horizontaloutside top surface of Post 28 and face 113 of Post 28 respectively.Since the horizontal surfaces of dado cut 39 and lower surface 34 ofSide Beam 24a rest entirely on the cross-sectional area of Post 28, thejoined horizontal faces 108-117 of Side Beam 24a and Post 28 do not bearthe weight of any load on junction 100 of Deck 20. As at corner junction50, an aperture is bored perpendicularly into the upper surface of thebeam into the end of face 117 and fastening means, such as pin 36,inserted therein. If a sub-flooring 31 or decking 33 is to be installed(as shown in FIGS. 1 and 4), pin 36, and other fastening means (notshown in FIG. 1 and 4) are used to secure it to frame 21. Also, as shownin phantom, a second-level Post 28, 30, 128, or 228 can be fitted, bymaking an inverse dado cut shape to two-sided seat formed by rim 41 tofittingly join the corresponding surface of sub-flooring 31. Theaperture is made through sub-flooring 31 and into the second-level postand pin 36 is inserted therethrough and therein. By using theabove-described construction, junction 100 is held together by the forceof gravity. In this way, the more weight added to Deck 20, the tighterand more secure, over and above the security built therein, it will be.

FIG. 4 is a perspective view of an alternate embodiment showing aone-level framed deck 120 (shown partially cut-away) having a CenterBeam 122 for the purpose of supporting an increased load. Deck 120 hasoppositely-facing Face Beams 22a,b joined and supported at their ends bycorner junction 50 and Corner Post 30 to oppositely-facing Side Beams24a,b (only Side Beam 24a is shown) and has interval junctions 100, allsimilar to deck 20, and can be covered by a subflooring 31 or decking 33as shown in FIG. 1 (only 31 shown in FIG. 4, partially cut-away). CenterBeam 122 is formed into a member with a cross-sectional shapesubstantially similar to the letter "T" by making dado cuts 139, similarto dado cuts 39 as explained above in FIG. 2, on opposite side facesalong the length of the beam.

FIG. 5 shows an isolated and expanded perspective view, taken at numeralV, of junction 150 showing how the end of Center Beam 122 is joined withthe top of Extension Post 128 and an intermediate section of a Face Beamor Side Beam (only Side Beam 24a is shown). Beam 24a, has, atprespecified intervals, a notch 127a cut in the edge formed by dado cut38, by known techniques, to form vertical faces 125a, 126a, and 130a,and horizontal face 131a. Opposed Side Beam 24b has a similar notch 127b(only 127a is shown in FIG. 5) therein, to present a "mirror image" whenthe two beams are set opposite one another. When a Center Beam 122 is tojoin opposed Side Beams 24a,b, notches 127a,b are cut at appropriateintervals into the edges formed by dado cuts 38 to fittingly receive theends of Center Beam 122. The ends of beam 122 have part of the stem ofthe "T", cut away, as with a dado cut or other means, from the undersideof the beam to provide a vertical face 123a, a horizontal face 137a, andleave the horizontal face 136a. The end of Center Beam 122 and Side Beam24a are joined at corresponding faces 136a-130a, 137a-131a, and theupper-outside faces of Center Beams 122-126a and 125a respectively.

Extension Posts 128 are engineered to provide, at the end joined tojunction 150, a one-sided seat 134 for the combination of the Side Beamand Center Beam 24a, 122, respectively, to fit therein. As seen in FIG.5, an end of Post 128 has a dado cut made along a plane substantiallyperpendicular to the sides thereof and into the end of the post apredetermined distance to remove a substantially cubical section of woodtherefrom to form seat 134. This cut provides vertical face 135 andhorizontal face 133. The combination of the vertical surfaces of dadocuts 39 of Side Beam 24a, fittingly joined to corresponding verticalface 135 of Post 128, and Face Beam 22b, fittingly joined tocorresponding vertical face 86 of Post 30 (previously shown in FIG. 2),prevents junction 150 from any degree of freedom in the horizontaldirection. The combination of the horizontal surface of dado cut 39, andlower surfaces 34 and 132 of Side Beam 24a and Center Beam 122 arefittingly joined to corresponding horizontal top faces of 135 and 133,respectively, of Post 128. Since the horizontal surface of dado cut 39and lower surfaces 34 and 132 of Side Beam 24a and Center Beam 122 restentirely on the horizontal cross-sectional area of Post 128, the joinedhorizontal faces 131a-137a of Side Beam 24a and Center Beam 122 do notbear the weight of any load on junction 150, nor on Deck 120. Anaperture 88 is bored perpendicular to the upper surface of junction 150,through beams 122 and 24a and into face 133 and fastening means, such asa pin 36, inserted therein. If subflooring 31 or decking 33 is to beinstalled (as shown in FIGS. 1 and 4) pin 36, and other fastening means(not shown in FIGS. 1 and 4) are used to secure it to frame 121. Also,as shown in phantom, a second-level Post 28, 30, 128, or 228 can befitted, by making an inverse dado cut shape to one-sided seat formed byrim 41 to fittingly join the corresponding top surface of sub-flooring31. By using the above-described construction, junction 150 is heldtogether by the forces of gravity. In this way, the more weight added toDeck 120, the tighter and more secure, over and above the security builttherein, it will be.

Additionally, at specified intervals, Beam 122 has further dado notches129 cut from the top side of the beam and at substantially right anglesto its longitudinal dimension, to fittingly receive joists 26 (shown inphantom in FIG. 5).

FIG. 6, an isolated, expanded and perspective view taken at numeral VIfrom FIG. 4, shows a junction 200 where a Center Post 228 supportinglyand fittingly meets the underside of Center Beam 122 at a position wherea joist 26 (shown in phantom) is held in a notch 129. The end of post228 that is to be joined to Center Beam 122 has a pre-engineered dadocut 234 made along a plane substantially perpendicular to the sidesthereof and into the end of the post a predetermined distance, to removea substantially rectangular section of wood exactly the width andthickness of the lower stem of the "T" of Center Beam 122. This cutprovides vertical and horizontal surfaces 238, 239, and 235,respectively, and leaves horizontal surfaces 236 and 237. Post 228 isplaced immediately below a predetermined notch 129. The outside surfacesof Center Beam 122, formed by dado cuts 139, and the surfaces of Post228, formed by dado cut 234, are fittingly joined at corresponding faces238 and 239--vertical surfaces of dado cuts 139, 236 and 237--horizontalsurfaces of dado cuts 139, and 235-132. An aperture 88 is bored, in aperpendicular direction to junction 200, through joist 26, the stem ofthe "T" of Center Beam 122, and into horizontal surface 235 of CenterPost 228. Fastening means, such as the combination of the verticalsurfaces of dado cuts 139 of Center Beam 122 fittingly joined tocorresponding vertical surfaces 238 and 239 of Center Post 228 and thecombination of pin 36 fittingly joined into aperture 88 prevent junction200 from any degree of freedom in the horizontal direction. When thesubflooring 31 is installed, junction 200 is isolated from the surfacesabove. Since the combination of the horizontal surfaces of dado cuts 139and lower surface 132 of Center Beam 122 are fittingly Joined tocorresponding horizontal surfaces 236,237, and 235, respectively, ofCenter Post 228, the joined horizontal faces of joist 26 and notch 129do not bear the weight of any load on subflooring 31. The joinedcombination of aperture 88 and pin 36 may extend through subflooring 31and into the bottom of a second level post 28, 30, 128 or 228. By usingthe above-described construction, junction 200 is held together by theforces of gravity. The more weight added to subflooring 31, andtherefore Deck 120, the tighter and more secure, over and above thesecurity built therein it will be.

It is understood that the above described embodiment is only one ofthose possible within the scope of the present invention. For instance,the bottom level posts used to support frame 21 can be either a cementfoundation or individual anchoring sites. These and other changes mayall be made within the spirit of the disclosure and the scope of theappended claims.

I claim:
 1. A junction of frame members for supporting a loadcomprising:a) a first horizontal member, the first horizontal memberhaving an end which is formed with a first generally rectangularcut-out, the first cut-out defining five distinct surfaces, b) a secondhorizontal member, the second horizontal member having an end which isformed with a second generally rectangular cut-out, the second cut-outdefining five distinct surfaces, the second cut-out being shaped to matewith the first cut-out, and c) a post member, wherein the first andsecond horizontal members are held in mating relationship such that eachof the five surfaces of the first cut-out are held in abutment,respectively, with each of the five surfaces of the second cut-outwithout regard to any abutment with the post member, and wherein thefirst and second horizontal members have lower surfaces which are notpart of said first and second cut-outs, and wherein the lower surfacesof both horizontal members rest upon the post member.
 2. The junction ofclaim 1, wherein the post member has an end which is formed with a thirdcut-out, the third cut-out defining two vertical extensions and ahorizontal seat, and wherein the lower surfaces of the horizontalmembers rest upon the horizontal seat.
 3. The junction of claim 1,further comprising a second-level post, the second-level post having acut-out in an end thereof, the cut-out of the second-level post beingshaped to mate with the cut-outs of the first and second horizontalmembers, the second-level post having an aperture aligned with anaperture in one of the first and second horizontal members, whereinthere is a pin which extends through a portion of the second-level postand one of the horizontal members.
 4. A junction of frame members forsupporting a load comprising:a) a first horizontal member, the firsthorizontal member having an inner section and an outer section, theinner and outer sections both having generally rectangularcross-sections, the inner and outer sections being adjacent to eachother and generally parallel to each other and mutually offset to definea downwardly extending lower portion of the inner section and anupwardly extending upper portion of the outer section, the inner sectionhaving an upper portion, b) a second horizontal member, the secondhorizontal member having an inner section and an outer section, theinner and outer sections both having generally rectangularcross-sections, the inner and outer sections being adjacent to eachother and generally parallel to each other and mutually offset to definea downwardly extending lower portion of the inner section and anupwardly extending upper portion of the outer section, the inner sectionhaving an upper portion, c) the first horizontal member having an end inwhich there is a cut-out in the lower portion of the inner section ofsaid first horizontal member, such that the upper portion of the innersection of the first horizontal member extends longitudinally beyond thelower portion of the inner section, and the outer section extendslongitudinally beyond the upper portion of the inner section, d) thesecond horizontal member having an end in which there is a cut-out inthe upper portion of the inner section of said second horizontal member,the cut-out having a longitudinal extent, and wherein the outer sectionextends along the longitudinal extent of the cut-out, wherein the firstand second horizontal members are matingly engaged at said ends, andwherein the first and second horizontal members sit on a post member. 5.The junction of claim 4, wherein the post member has an end which isformed with a cut-out comprising two vertical extensions and ahorizontal seat, and wherein the lower portions of the inner sections ofthe first and second horizontal members sit on the horizontal seat. 6.The junction of claim 5, wherein the outer sections of the horizontalmembers both have a bottom, and wherein the vertical extensions of thepost member have a height which extends up to the bottom of the outersections of the horizontal members.
 7. In a junction of frame membersfor supporting a load, the junction being formed of first and secondhorizontal members disposed on a vertical post, both horizontal memberscomprising an inner section having a generally rectangular cross-sectionand an outer section having a generally rectangular cross-section, theouter section extending above the inner section such that the outersection defines a flange extending along both horizontal members, theimprovement wherein:the first horizontal member has an end having acut-out which defines a plurality of surfaces, the second horizontalmember has an end having a cut-out which defines a plurality ofsurfaces, wherein the surfaces of the cut-outs of the respectivehorizontal members are shaped to mate with each other, wherein the innersection of the first horizontal member and the inner section of thesecond horizontal member bear against each other along a plurality ofsurfaces, and wherein the outer sections of the first and secondhorizontal members bear against each other.
 8. The improvement of claim7, wherein the first and second horizontal members sit on a post member.9. The improvement of claim 8, wherein the post member has an end whichis formed with a cut-out comprising two vertical extensions and ahorizontal seat, and wherein the inner sections of the first and secondhorizontal members sit on the horizontal seat.
 10. The improvement ofclaim 9, wherein the outer sections of the horizontal members both havea bottom, and wherein the vertical extensions of the post member have aheight which extends up to the bottom of the outer sections of thehorizontal members.
 11. The improvement of claim 7, wherein the innersection of the first horizontal member and the inner section of thesecond horizontal member bear against each other along three pairs ofsurfaces, wherein the inner section of the first horizontal member andthe outer section of the second horizontal member bear against eachother along a pair of surfaces, and wherein the outer sections of thefirst and second horizontal members bear against each other along a pairof surfaces, all of said pairs of surfaces being distinct from any ofsaid other pairs of surfaces.